Various outboard-motor attachment assemblies of the aforementioned kind are known to the art.
In order to illustrate the state of the art, attention is drawn to the outboard-motor attachment assembly described in Swedish Patent Application 8102830-0. The attachment assembly of this application comprises two parts which are pivotally connected together through a pivot shaft and of which a first part is intended to be firmly secured to the stern transom of a boat and a second part is provided with an edge portion for supporting the outboard motor. It is proposed in this patent application that the pivot shaft between the two attachment parts is positioned over the edge portion at such a height thereabove that the pivot shaft is located adjacent the upper edge of the outboard motor.
In this known attachment assembly, the setting angle or position between the two attachment parts is adjusted with the aid of a hydraulic piston-cylinder device.
U.S. Pat. No. 4,363,629 discloses a marine power means comprising a first part in the form of a stern-transom attachment means arranged to be attached to the transom of a boat, and a second part in the form of a so-called transom attachment. There is also provided a pivot shaft which is arranged to connect the first part of the power means with the second part thereof, in a manner to enable the parts to be rotated in relation to one another about the pivot shaft.
This known assembly also includes a first hydraulic piston-cylinder device for adjusting the outboard motor to different angular positions in the fulfillment of a trimming function, and a second hydraulic piston-cylinder device for fulfillment of a desired tilting function of the outboard motor.
It is also known that the attitude of a boat in the water during passage therethrough can be adjusted by changing the angular position of the outboard motor in relation to the stern transom. A small angle causes the forward part of the boat to be pressed down, while a large angle causes the forward part of the boat to be lifted.
It is also known that a very large force is required to effect the aforementioned relative angular changes when the outboard motor is running, and that this force is much greater than the force required to rotate the outboard motor through much large angles when the motor is not running.
This angular adjustment, which is desirable during passage of the boat through the water, is referred to as the trimming function, while the angular adjustment desirable when the motor is not running is referred to as the tilting function.
It is also known that angular adjustment in respect of the trimming function must be more precise, despite the high forces generated, than the angular adjustment in respect of the tilting function.
It should also be mentioned that in the U.S. Pat. No. 4,362,513 it is previously known to use a toggle linkage to adjust the motor relative the boat within the trimming area and have a hydraulic means acting with a force on the common pivoting axis of the two links, usually having an obtuse angle.